Slicer  5.1
Slicer is a multi-platform, free and open source software package for visualization and medical image computing

Widgets → Base Relation

File in Modules/Loadable/Markups/WidgetsIncludes file in Base
qSlicerMarkupsPlaceWidget.hQTGUI / qSlicerWidget.h
qSlicerSimpleMarkupsWidget.hQTGUI / qSlicerWidget.h